The Holy Spirit is the third person in our triune God – God the Father, God the Son and God the Holy Spirit.
The Holy Spirit is our comforter and our counselor (advisor). Jesus told that it is good that He is going, so that Holy Spirit will be sent to be with us and for us. The person of the Holy Spirit has such a very unique and special place of honor. We should therefore neither be quenching the Holy Spirit, nor should we be grieving the Holy Spirit. But unless we understand what these mean, we may not know if we slip into this wrong doing.